Oil-in-water type emulsification composition containing uv wavelength conversion substance

ABSTRACT

To provide a novel oil-in-water type emulsified composition, comprising a UV wavelength conversion substance and a water-soluble alkyl-substituted polysaccharide derivative.

FIELD

The present invention relates to an oil-in-water type emulsified composition having a cell activation action and comprising a UV wavelength conversion substance.

BACKGROUND

Ultraviolet is considered to generate free radicals in vivo and thereby cause oxidation of sebum and damage to cellular DNA. Examples of the damage caused by ultraviolet to skin include adverse effects such as skin cancer, photoaging, spots, wrinkles, and inflammation. These are undesirable from a health and beauty perspective. Although ultraviolet has been used for the purpose of sterilization, it is currently focused on protection from rather than active use of ultraviolet in consideration of the balance with harmful effects caused by ultraviolet.

Thus, many measures have been taken to protect skin from ultraviolet. Examples thereof include use of sunscreens, indoor activities avoiding sunlight, and use of UV-cut hats or clothing, and ultraviolet cut films.

For example, PTL 12 describes in Formulation Example 2 an oil-in-water type skin cosmetic containing a fluorescent zinc oxide but not containing a water-soluble alkyl-substituted polysaccharide derivative. PTL 12 does not describe a UV wavelength conversion substance for bringing about a cell activation effect.

CITATION LIST Patent Literature

[PTL 1] Japanese Registered Patent Publication No. 6424656

[PTL 2] Japanese Registered Patent Publication No. 6361416

[PTL 3] WO 2018/004006

[PTL 4] Japanese Unexamined Patent Publication (Kokai) No. 2018-131422

[PTL 5] Japanese Unexamined Patent Publication (Kokai) No. 5-117127

[PTL 6] Japanese Registered Patent Publication No. 4048420

[PTL 7] Japanese Registered Patent Publication No. 4677250

[PTL 8] Japanese Registered Patent Publication No. 3303942

[PTL 9] Japanese Unexamined Patent Publication (Kokai) No. 2017-88719

[PTL 10] WO 2018/117117

[PTL 11] Japanese Unexamined Patent Publication (Kokai) No. 2015-120682

[PTL 12] Japanese Unexamined Patent Publication (Kokai) No. 2017-122075

SUMMARY Technical Problem

An object of the present invention is to provide a novel oil-in-water type emulsified composition having a cell activation action utilizing ultraviolet.

Solution to Problem

The present inventors have conducted intensive studies so that ultraviolet can be effectively used for skin. As a result, the present inventors have conceived of an oil-in-water type emulsified composition having an excellent cell activation action and containing a UV wavelength conversion substance.

The present application provides the following inventions.

(1) An oil-in-water type emulsified composition comprising (A) a UV wavelength conversion substance and (B) a water-soluble alkyl-substituted polysaccharide derivative. (2) The oil-in-water type emulsified composition according to (1), wherein the (A) UV wavelength conversion substance comprises an inorganic UV wavelength conversion substance. (3) The oil-in-water type emulsified composition according to (2), wherein the inorganic UV wavelength conversion substance comprises one or more selected from the group of a zinc oxide phosphor, a magnesium titanate phosphor, and a calcium phosphate phosphor. (4) The oil-in-water type emulsified composition according to (1), wherein the (A) UV wavelength conversion substance comprises an organic UV wavelength conversion substance.

-   -   (5) The oil-in-water type emulsified composition according to         (4), wherein the organic UV wavelength conversion substance         comprises one or more selected from the group of: phycocyanin,         phycoerythrocyanin, phycoerythrin, vitamin K, vitamin B1,         vitamin B2, vitamin B2 derivatives, vitamin B6, vitamin B12,         folic acid, salicylic acid, gardenia color, capsicum color,         capsicum extract, paprika color, perilla color, red cabbage         color; a blue phosphor comprising an amorphous silica particle,         cerium, and phosphorus and/or magnesium; a red phosphor         comprising a europium-activated compound of a mixed crystal of         an alkaline earth metal sulfide and a gallium compound; a zinc         oxide phosphor, a phosphor doped with a sulfur-containing         compound, a magnesium titanate phosphor and a calcium phosphate         phosphor.         (6) The oil-in-water type emulsified composition according to         any one of (1) to (5), comprising both an inorganic UV         wavelength conversion substance and an organic UV wavelength         conversion substance as the (A) UV wavelength conversion         substance.         (7) An oil-in-water type emulsified composition comprising: (A′)         one or more selected from the group of phycocyanin,         phycoerythrocyanin, phycoerythrin, vitamin K, vitamin B1,         vitamin B2, vitamin B2 derivatives, vitamin B6, vitamin B12,         folic acid, salicylic acid, gardenia color, capsicum color,         capsicum extract, paprika color, perilla color, red cabbage         color; a blue phosphor comprising an amorphous silica particle,         cerium, and phosphorus and/or magnesium; a red phosphor         comprising a europium-activated compound of a mixed crystal of         an alkaline earth metal sulfide and a gallium compound; a zinc         oxide phosphor, a phosphor doped with a sulfur-containing         compound, a magnesium titanate phosphor, and a calcium phosphate         phosphor, and         (B) a water-soluble alkyl-substituted polysaccharide derivative.         (8) The oil-in-water type emulsified composition according to         any one of (1) to (7), wherein the (B) water-soluble         alkyl-substituted polysaccharide derivative comprises a C14-22         alkyl-substituted polysaccharide derivative.         (9) The oil-in-water type emulsified composition according to         (8), wherein the C14-22 alkyl-substituted polysaccharide         derivative comprises a stearoxyhydroxypropyl methylcellulose.         (10) The oil-in-water type emulsified composition according to         any one of (1) to (9), further comprising (C) a UV absorber         and/or (D) a UV scattering agent.         (11) The oil-in-water type emulsified composition according to         any one of (1) to (10), wherein further (E) a powder is         dispersed in an oil phase.         (12) The oil-in-water type emulsified composition according to         any one of (1) to (11), which is a sunscreen cosmetic.         (13) The oil-in-water type emulsified composition according to         any one of (1) to (12), which exhibits a fluorescence intensity         increasing effect.         (14) The oil-in-water type emulsified composition according to         any one of (1) to (13), which exhibits a cell activation effect.

Advantageous Effects of Invention

The UV wavelength conversion substance of the present invention is suitable for effectively utilizing ultraviolet to activate skin cells. The constituent composition of the oil-in-water type emulsified composition of the present invention is suitable so that the UV wavelength conversion substance converts ultraviolet to visible light. Specifically, the oil-in-water type emulsified composition of the present invention can impart a refreshing feel after use, compared to a water-in-oil type. Conventionally, since ultraviolet is not preferable for skin, it is a technical common knowledge in this field to take measures to avoid exposing skin to ultraviolet as much as possible. However, the present invention is based on the knowledge that conversely a UV wavelength conversion substance utilizes ultraviolet to activate cells and thereby provide a preferable action on skin, and is surprising. Thus, the oil-in-water type emulsified composition of the present invention may lead to an improvement in the quality of life, such that even those who have avoided ultraviolet as much as possible for a reason of beauty or health may feel like going out actively.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic diagram of Experiments 1 and 2.

FIG. 2 shows the cell activity at UV irradiation using each ultraviolet in Experiment 1. The vertical axis indicates relative fluorescence intensity (au).

FIG. 3 shows the cell activity at UV irradiation of each intensity using C-phycocyanin in each concentration in Experiment 2 as the relative fluorescence intensity (au).

FIG. 4 is a schematic diagram of Experiment 3.

FIG. 5 shows the cell activity when irradiating cells having cell activity temporarily reduced in Experiment 3 with UV using C-phycocyanin as relative fluorescence intensity (au) (P test).

DESCRIPTION OF EMBODIMENTS

The present invention will be described below in detail with reference to specific embodiments. However, the present invention is not limited to the following embodiments, and can be carried out in any embodiments without departing from the spirit of the present invention.

All of the patent publications, unexamined patent publications, and non-patent literature cited in the present disclosure are incorporated by reference in their entirety into the present disclosure for all purposes.

In the present disclosure, “to” when applied to numerical values refers to a range of values that fall within a range that is greater than or equal to a defined reference value and less than or equal to a defined reference value.

(A) UV Wavelength Conversion Substance

The emulsified composition of the present invention contains a UV wavelength conversion substance as an active component. The phrase “UV wavelength conversion substance” refers to a substance which converts the wavelength of ultraviolet contained in incident light to outgoing light with a wavelength longer than the wavelength of ultraviolet. The phrase “organic UV wavelength conversion substance” refers to a UV wavelength conversion substance which is an organic compound, and the phrase “inorganic UV wavelength conversion substance” refers to a UV wavelength conversion substance which is an inorganic compound.

The ultraviolet may contain UVA, UVB, or UVC. In one embodiment, the ultraviolet is light having a peak wavelength of 200 nm to 400 nm. Further, incident light, for example, sunlight, may contain ultraviolet. Furthermore, the incident light may be ultraviolet or artificially generated ultraviolet may be used.

The outgoing light emitted from the UV wavelength conversion substance has a longer wavelength than ultraviolet and has a peak wavelength of preferably 500 nm to 700 nm. The outgoing light may have one or more peaks, for example, but not limited to, at 510 nm, 520 nm, 530 nm, 540 nm, 550 nm, 560 nm, 570 nm, 580 nm, 590 nm, 600 nm, 610 nm, 620 nm, 630 nm, 640 nm, 650 nm, 660 nm, 670 nm, 680 nm, 690 nm, 700 nm, or within any range therebetween or may be red light, orange light, green light, or blue light. In one embodiment, the main wavelength exhibited by the light emitted from the UV wavelength conversion substance when excited by 200 nm to 400 nm excitation light is 500 nm to 700 nm.

Examples of the UV wavelength conversion substance include the following components: phycobiliproteins such as phycocyanin (allophycocyanin, C-phycocyanin, R-phycocyanin), phycoerythrocyanin, phycoerythrin (B-phycoerythrin, b-phycoerythrin, C-phycoerythrin, R-phycoerythrin); natural or synthetic components such as vitamin A, n-carotene, vitamin K, vitamin B1, vitamin B2, vitamin B6, vitamin B12, folic acid, niacin, salicylic acid, lycopene, capsicum extract, capsicum color, paprika color, gardenia color, safflower color, turmeric color, cochineal color, perilla color, red cabbage color, flavonoid, carotenoid, quinoid, porphyrins, anthocyanins, and polyphenols; colors such as Red No. 401, Red No. 227, Red No. 504, Red No. 218, Orange No. 205P, Yellow No. 4, Yellow No. 5, Green No. 201, pyranine conc., Blue No. 1, 2,4-diaminophenoxyethanol hydrochloride, Alizuline Purple SS, Purple No. 401, Black No. 401, Herindon pink, Yellow No. 401, Benzidine yellow G, Blue No. 404, Red No. 104, and meta-aminophenol; phosphors of an inorganic compound doped to exhibit a fluorescence property, such as the blue phosphor containing an amorphous silica particle, cerium, and phosphorus and/or magnesium described in Japanese Registered Patent Publication No. 6424656, the red phosphor containing a europium-activated compound of a mixed crystal of an alkaline earth metal sulfide and a gallium compound described in Japanese Registered Patent Publication No. 6361416, the zinc oxide phosphor described in WO 2018/004006, the zinc oxide phosphor described in Japanese Unexamined Patent Publication (Kokai) No. 2018-131422, the inorganic phosphor described in Japanese Unexamined Patent Publication (Kokai) No. 5-117127 (hereinafter, a phosphor derived from zinc oxide is referred to as a “zinc oxide phosphor”). In one embodiment, the inorganic phosphor is one or more phosphors selected from phosphors of zinc oxide represented by ZnO:Zn, Zn_(1+z), or ZnO_(1−x), doped with a sulfide and/or a sulfate, such as zinc sulfide and zinc sulfate, described in WO 2018/004006, magnesium titanate phosphors of a magnesium titanate such as MgTiO₃ or Mg₂TiO₄ doped with manganese (hereinafter referred to as magnesium titanate is referred to as a “magnesium titanate phosphor”), and calcium phosphate phosphors of a calcium phosphate such as Ca(H₂PO₄)₂, CaHPO₄, or Ca₃(PO₄)₂ doped with cerium.

Further, the inorganic UV wavelength conversion substance which is an inorganic phosphor may be subjected to a surface treatment. Examples of the surface treatment include a silane compound treatment (octyltriethoxysilane), a silicone compound treatment, a fluorine-modified silicone compound treatment, a fluorine compound treatment, a higher fatty acid treatment (stearic acid, etc.), a higher alcohol treatment, a fatty acid ester treatment, a metal soap treatment, an amino acid treatment, and an alkyl phosphate treatment.

UV wavelength conversion substance may be obtained by a method of extraction from natural products such as animals, plants, and algae or an artificial method such as chemical synthesis. For example, phycobiliproteins may be prepared from blue-green algae such as Spirulina platensis, red algae such as Porphyridium cruentum, and other algae by the extraction method described in, for example, Japanese Registered Patent Publication No. 4048420, Japanese Registered Patent Publication No. 4677250, or Japanese Registered Patent Publication No. 3303942. Zinc oxide phosphors may be produced by the method described in, for example, WO 2018/004006, Japanese Unexamined Patent Publication (Kokai) No. 2018-131422, or Japanese Unexamined Patent Publication (Kokai) No. 5-117127. Magnesium titanate phosphors may be produced by the method described in Japanese Unexamined Patent Publication (Kokai) No. 2017-88719. Calcium phosphate phosphor may be produced by the method described in WO 2018/117117.

These UV wavelength conversion substances may consist of or contain these exemplified components, which may be used alone or in combination of two or more. For example, to the phycobiliprotein or inorganic phosphor, there may be added another wavelength conversion substance such as vitamin B (vitamin B1, vitamin B2, vitamin B6, or vitamin B12) to aim for a synergistic effect. Note that these components are merely examples and any substance which can bring about a wavelength conversion effect can be used in the present invention.

Any derivative of vitamin B2, which is a UV wavelength conversion substance, may be used as long as the derivative is a UV wavelength conversion substance. Examples of the vitamin B2 derivatives include riboflavin acetate ester, riboflavin butyrate, riboflavin phosphate (may be a sodium or mono-diethanolamine salt), flavin mononucleotide, flavin adenine dinucleotide, riboflavin tetrabutyrate, and riboflavin tetranicotinate. Derivatives of lixoflavin, which is a stereoisomer of riboflavin, may be used.

The content of the UV wavelength conversion substance in the oil-in-water type emulsified composition of the present invention is not particularly limited as long as the wavelength conversion effect of the present invention is not impaired. The content can be appropriately determined in accordance with the type of the UV wavelength conversion substance or the application of the oil-in-water type emulsified composition containing the UV wavelength conversion substance. The range thereof is not limited and may be, for example, 0.001 to 99.99% by weight, 0.001 to 10% by weight, 0.01 to 99.99% by weight, 0.01 to 10% by weight, 0.1% to 99.9% by weight, or 0.1 to 10% by weight.

As one aspect of the present invention, the UV wavelength conversion substance of the oil-in-water type emulsified composition contains a zinc oxide phosphor. In the oil-in-water type emulsified composition of the present invention, preferably, the content of a zinc oxide phosphor relative to the total of the oil-in-water type emulsified composition is 0.1% by weight or more, preferably 1.0% by mass or more, more preferably 1.5% by weight or more, or even more preferably 2% by weight or more, and 20% by weight or less, preferably 15% by weight or less, more preferably 10% by weight or less, or even more preferably 5% by weight or less. The content relative to the total of the oil-in-water type emulsified composition is 0.01 to 99.99% by weight, 0.1 to 99.9% by weight, 0.1 to 50% by weight, 0.1 to 40% by weight, 0.1 to 30% by weight, 0.1 to 20% by weight, 0.1 to 10% by weight, or 1 to 10% by weight.

As one aspect of the present invention, the UV wavelength conversion substance of the oil-in-water type emulsified composition contains a magnesium titanate phosphor. In the emulsified composition of the present invention, preferably, the content of a magnesium titanate phosphor relative to the total of the oil-in-water type emulsified composition is 0.1% by weight or more, preferably 1.0% by mass or more, more preferably 1.5% by weight or more, or even more preferably 2% by weight or more, and 20% by weight or less, preferably 15% by weight or less, more preferably 10% by weight or less, or even more preferably 5% by weight or less. The content relative to the total of the oil-in-water type emulsified composition is 0.01 to 99.99% by weight, 0.1 to 99.9% by weight, 0.1 to 50% by weight, 0.1 to 40% by weight, 0.1 to 30% by weight, 0.1 to 20% by weight, 0.1 to 10% by weight, 0.5 to 10% by weight, or 1 to 10% by weight.

As one aspect of the present invention, the UV wavelength conversion substance of the oil-in-water type emulsified composition contains phycocyanin. In the oil-in-water type emulsified composition of the present invention, preferably, the content of a phycocyanin relative to the total of the oil-in-water type emulsified composition is 0.00001% by weight or more, preferably 0.0001% by mass or more, and 20% by weight or less, preferably 15% by weight or less, more preferably 10% by weight or less, or even more preferably 5% by weight or less. The content relative to the total of the oil-in-water type emulsified composition is 0.00001 to 99.99% by weight, 0.0001 to 99.9% by weight, 0.0001 to 50% by weight, 0.0001 to 40% by weight, 0.0001 to 30% by weight, 0.0001 to 20% by weight, 0.0001 to 10% by weight, 0.0001 to 5% by weight, 0.001 to 5% by weight, 0.01 to 5% by weight, 0.05 to 5% by weight, 0.1 to 5% by weight, 0.1 to 3% by weight, or 0.1 to 1% by weight.

As one aspect of the present invention, the UV wavelength conversion substance of the oil-in-water type emulsified composition contains vitamin B2. In the oil-in-water type emulsified composition of the present invention, preferably, the content of vitamin B2 relative to the total of the oil-in-water type emulsified composition is 0.00001% by weight or more, preferably 0.0001% by weight or more, and 20% by weight or less, preferably 15% by weight or less, more preferably 10% by weight or less, or even more preferably 5% by weight or less. The content relative to the total of the oil-in-water type emulsified composition is 0.00001 to 99.99% by weight, 0.0001 to 99.9% by weight, 0.0001 to 50% by weight, 0.0001 to 40% by weight, 0.0001 to 30% by weight, 0.0001 to 20% by weight, 0.0001 to 10% by weight, 0.0001 to 5% by weight, 0.001 to 5% by weight, 0.005 to 5% by weight, 0.01 to 5% by weight, 0.01 to 1% by weight, 0.01 to 0.5% by weight, or 0.01 to 0.1% by weight.

Examples of cell activation include, but are not limited to, promoting metabolism and turnover, improving a function, promoting proliferation, inhibiting oxidation, improving resistance to fatigue and external stimuli, and inhibiting loss of function and activity in cells, such as dermal fibroblasts and/or keratinocytes, of animals including humans. When skin cells are activated, effects such as prevention of or improvement from wrinkles, spots, skin aging, and photoaging can be expected.

The cell activation effect may be measured by measuring, for example, the viability, reducing ability, or proliferation of living cells using AlamarBlue as in the Examples. Any method can be used such as another dye assay, mitochondrial membrane potential-dependent dye assay, intracellular cytochrome c assay, elastase cleavage dye assay, ATP, ADE assay, glycolytic flux and oxygen consumption assay, collagen assay, photoaging assay, collagen glycation assay, inflammatory substances (interleukin 1α, interleukin 8, tumor necrosis factor α) assay, skin barrier function-related protein (corneodesmosin, sphingomyelin phosphodiesterase, filaggrin, involucrin, loricrin, transglutaminase 1, caspase 14) assay, angiogenesis modulator (VEGF-A, ANGPT1) assay, oxidation and/or skin stress-related protein (aromatic hydrocarbon receptor repressor, cytochrome P4501B1, aromatic hydrocarbon receptor repressor, heme oxygenase 1) assay, or hyaluronic acid assay.

The cosmetic of the present invention is suitable for performing the function of a UV wavelength conversion substance and for alleviating, or more positively improving or restoring skin damage during and after ultraviolet irradiation by activating cells, and more specifically, is suitable for collagen production or hyaluronic acid production by fibroblasts and inhibition of damage caused by photoaging and for inhibiting oxidation stress of keratinocytes, enhancing a barrier function, suppressing an inflammatory reaction, and suppressing the glycation of collagen and angiogenesis in skin.

Fluorescence intensity can be measured using a spectrofluorometer by irradiating with ultraviolet a coating film of the composition on the surface of a substrate, as in the Examples. The substrate may be a resin substrate composed of a polymethyl methacrylate (PMMA), nylon, or acrylic plate or an inorganic plate of glass or quartz. For example, a PMMA plate having V-shaped grooves on its surface (also refer to as “S plate”: Japanese Registered Patent Publication No. 4453995) can be used. As the fluorescence intensity, a fluorescence value at a specific single wavelength or an integrated value in a specific wavelength region may be used.

(B) Water-Soluble Alkyl-Substituted Polysaccharide Derivative

The oil-in-water type emulsified composition of the present invention contains a water-soluble alkyl-substituted polysaccharide derivative. The phrase “water-soluble alkyl-substituted polysaccharide derivative” refers to an alkyl group-substituted polysaccharide that functions as a water-soluble thickener in an oil-in-water type composition. The “alkyl group” of the water-soluble alkyl-substituted polysaccharide derivative is not particularly limited as long as the alkyl-substituted polysaccharide derivative is water-soluble, and has, for example, 1 to 35, 5 to 30, 6 to 26, 10 to 25, or 14 to 22 carbon atoms. The alkyl group may be bound directly to the polysaccharide, or may be bound to the polysaccharide as an indirect substituent. The “polysaccharide” of the water-soluble alkyl-substituted polysaccharide derivative is a compound in which a plurality of monosaccharides are bound. Examples thereof include sclerotium gum, Arabic gum, alcaligenes-producing polysaccharide, cellulose, guar gum, carrageenan, hyaluronic acid, chondroitin sulfate, tuberose polysaccharide, tremella fuciformis polysaccharide, locust bean gun, dextrin, chitosan, inulin, and starch. The polysaccharide may be modified to bind an alkyl group. Examples thereof include methylcellulose, ethylcellulose, propylcellulose, butylcellulose, hydroxymethylcellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methylcellulose, carboxymethylcellulose, carboxyethylcellulose, and hydroxypropyl starch phosphate, and the hydroxy polysaccharide may have one or more hydroxyl groups. The number of saccharides constituting the polysaccharide is not particularly limited as long as the alkyl-substituted polysaccharide derivative is water-soluble, for example, 100 to 100000, 100 to 10000, 500 to 5000, 1000 to 5000 or 1000 to 4,000.

As a preferred aspect of the water-soluble alkyl-substituted polysaccharide derivative contained in the oil-in-water type emulsified composition of the present invention, PTL 11 (Japanese Unexamined Patent Publication (Kokai) No. 2015-120682) discloses an alkylcellulose (hereinafter referred to as “hydrophobically modified alkylcellulose”) hydrophobically modified with an alkyl group having 14 to 22 carbon atoms. The hydrophobically modified alkylcellulose is a compound in which a long chain alkyl group, which is a hydrophobic group, is introduced into a water-soluble cellulose ether modified body, represented by the following general formula (I):

where Rs, which may be the same or different, are each one or more groups selected from a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, —[CH2CH(CH3)O]m-H group (where m is an integer of 1 to 5, preferably 1 to 3), —CH2CH2OH group, and —CH2CH(OH)CH2OR′ group (where R′ is an alkyl group having 14 to 22 carbon atoms), provided that the —CH2CH(OH)CH2OR′ group must be contained; A is —(CH2)q- group (where q is an integer of 1 to 3, preferably 1), and n is an integer of 100 to 10000, preferably 500 to 5000. The hydrophobically modified alkylcellulose can be produced by the method described in PTL 11.

A preferred aspect of the water-soluble alkyl-substituted polysaccharide derivative contained in the oil-in-water type emulsified composition of the present invention contains stearoxyhydroxypropyl methylcellulose, for example, Sangelose® by Daido Chemical Corporation. A hydrophobically modified alkylcellulose with a weight average molecular weight (Mw) of about 300000 to 500000 (Sangelose® 60 series), a hydrophobically modified alkylcellulose with a weight average molecular weight (Mw) of about 700000 to 900000 (Sangelose® 90 series), or a mixture thereof can be used. A preferred aspect of the water-soluble alkyl-substituted polysaccharide derivative contained in the oil-in-water type emulsified composition of the present invention contains Sangelose® 60L or Sangelose® 90L, and a more preferred aspect contains Sangelose® 90L.

One aspect of the oil-in-water type emulsified composition of the present invention is an oil-in-water type emulsified composition comprising (A′) one or more selected from the group of phycocyanin, phycoerythrocyanin, phycoerythrin, vitamin K, vitamin B1, vitamin B2, vitamin B2 derivatives, vitamin B6, vitamin B12, folic acid, salicylic acid, gardenia color, capsicum color, capsicum extract, paprika color, perilla color, red cabbage color; a blue phosphor comprising an amorphous silica particle, cerium, and phosphorus and/or magnesium; a red phosphor comprising a europium-activated compound of a mixed crystal of an alkaline earth metal sulfide and a gallium compound; a zinc oxide phosphor, a phosphor doped with a sulfur-containing compound, a magnesium titanate phosphor, and a calcium phosphate phosphor, and (B) a water-soluble alkyl-substituted polysaccharide derivative. Another aspect of the oil-in-water type emulsified composition of the present invention is an oil-in-water type emulsified composition comprising (A′) one or more selected from the group of phycocyanin, phycoerythrocyanin, phycoerythrin, vitamin K, vitamin B1, vitamin B2, vitamin B2 derivatives, vitamin B6, vitamin B12, folic acid, salicylic acid, gardenia color, capsicum color, capsicum extract, paprika color, perilla color, red cabbage color; a blue phosphor comprising an amorphous silica particle, cerium, and phosphorus and/or magnesium; a red phosphor comprising a europium-activated compound of a mixed crystal of an alkaline earth metal sulfide and a gallium compound; a zinc oxide phosphor, a phosphor doped with a sulfur-containing compound, a magnesium titanate phosphor, and a calcium phosphate phosphor, and (B) a C14-22 alkyl-substituted polysaccharide derivatives. Still another aspect of the oil-in-water type emulsified composition of the present invention is an oil-in-water type emulsified composition comprising (A′) one or more selected from the group of phycocyanin, phycoerythrocyanin, phycoerythrin, vitamin K, vitamin B1, vitamin B2, vitamin B2 derivatives, vitamin B6, vitamin B12, folic acid, salicylic acid, gardenia color, capsicum color, capsicum extract, paprika color, perilla color, red cabbage color; a blue phosphor comprising an amorphous silica particle, cerium, and phosphorus and/or magnesium; a red phosphor comprising a europium-activated compound of a mixed crystal of an alkaline earth metal sulfide and a gallium compound; a zinc oxide phosphor, a phosphor doped with a sulfur-containing compound, a magnesium titanate phosphor, and a calcium phosphate phosphor, and (B) stearoxyhydroxypropyl methylcellulose.

(C) UV Absorber

UV absorbers absorb incident ultraviolet and are thus considered to indirectly inhibit the function of a UV wavelength conversion substance. However, surprisingly, the oil-in-water type emulsified composition of the present invention can contain a UV absorber and the function of a UV wavelength conversion substance can be exhibited.

The oil-in-water type emulsified composition of the present invention contains a UV absorber. The phrase “UV absorber” refers to a substance which absorbs ultraviolet and converts it to the energy of heat or infrared. The UV absorber that can be used in the present invention is not particularly limited as long as the function of the UV wavelength conversion substance is not directly impaired. Examples of the UV absorber include salicylic acid-based UV absorbers such as homomenthyl salicylate, ethylhexyl salicylate (octyl salicylate), homosalate, and triethanolamine salicylate; cinnamic acid-based UV absorbers such as 2-ethylhexyl para-methoxycinnamate, glyceryl diparamethoxycinnamate mono-2-ethylhexanoate, methyl 2,5-diisopropylcinnamate, 2,4,6-tris[4-(2-ethylhexyloxycarbonyl)anilino]-1,3,5-triazine, (hereinafter also referred to as “ethylhexyl triazone”), isopentyl trimethoxycinnamate trisiloxane, an isopropyl para-methoxycinnamate-diisopropylcinnamate ester mixture, and a diethanolamine p-methoxyhydrocinnamate salt; benzoylmethane UV absorbers such as 2-phenyl-benzimidazole-5-sulfuric acid, 4-isopropyldibenzoylmethane, and 4-tert-butyl-4′-methoxydibenzoylmethane; octocrylene, 2-ethylhexyl dimethoxybenzylidene dioxoimidazolidine propionate, 1-(3,4-dimethoxyphenyl)-4,4-dimethyl-1,3-pentanedione, cinoxate, methyl-O-aminobenzoate, 3-(4-methylbenzylidene)camphor, octyltriazone, hexyl diethylaminohydroxybenzoyl benzoate, bis(ethylhexyloxyphenol)methoxyphenyl triazine, and methylene bis-benzotriazolyl tetramethylbutylphenol. One or more selected therefrom can be contained in the oil-in-water type emulsified composition.

The total content of the UV absorber that can be contained in the oil-in-water type emulsified composition of the present invention is 0.5% by weight or more, preferably 1% by weight or more, more preferably 5% by weight or more, even more preferably 8% by weight or more, or most preferably 10% by weight or more, relative to the total of the oil-in-water type emulsified composition to function as a sunscreen and 40% by weight or less, preferably 30% by weight or less, more preferably 25% by weight or less, even more preferably 20% by weight or less, relative to the total of the oil-in-water type emulsified composition to avoid excessive absorption of ultraviolet contained in incident light. The total content of the UV absorber that can be contained in the oil-in-water type emulsified composition of the present invention is 0.5 to 40% by weight, 1 to 40% by weight, 1 to 30% by weight, 1 to 25% by weight, 1 to 20% by weight, 5 to 40% by weight, 5 to 30% by weight, 5 to 25% by weight, 5 to 20% by weight, 8 to 30% by weight, 8 to 25% by weight, or 8 to 20% by weight.

(D) UV Scattering Agent

UV scattering agents scatter incident ultraviolet and are thus considered to indirectly inhibit the function of a UV wavelength conversion substance. However, surprisingly, the oil-in-water type emulsified composition of the present invention can contain a UV scattering agent and the function of a UV wavelength conversion substance can be exhibited.

The oil-in-water type emulsified composition of the present invention may contain a UV scattering agent. The term “UV scattering agent” refers to a substance which can reflect/scatter ultraviolet and protect skin from ultraviolet. Examples of the material of the UV scattering agent that can be used in the present invention include titanium dioxide, zinc oxide other than component (A) or (A′), iron oxide, zirconium oxide, and aluminum oxide. The UV scattering agent may be fine particles or a composite thereof. The UV scattering agent preferably contains one or more selected from titanium dioxide and zinc oxide other than component (A) or (A′).

The titanium dioxide and zinc oxide used as the UV scattering agent may be titanium dioxide and zinc oxide used commonly in cosmetics. Preferably, those having superior dispersibility, such as those subjected to a surface treatment by a publicly known method, as needed, specifically those subjected to a hydrophobic treatment, can be contained in the oil-in-water type emulsified composition.

Examples of the surface treatment include a silicone treatment with methylhydrogen polysiloxane or methylpolysiloxane; a fluorine treatment with perfluoroalkyl phosphoric acid ester or perfluoroalcohol; an amino acid treatment with N-acylglutamic acid; an alkylalkoxysilane treatment with octyltriethoxysilane or octyltrimethoxysilane; and further, a lecithin treatment; a metal soap treatment; a fatty acid treatment; and an alkyl phosphate treatment. Thereamong, zinc oxide surface-treated with silicone is preferably used.

The silicone used for surface treatment is not particularly limited. Examples thereof include methylpolysiloxane, methylphenylpolysiloxane, methylhydrogen polysiloxane, methylcyclopolysiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane, octamethyltrisiloxane, tetradecamethylhexasiloxane, dimethylsiloxane-methyl (polyoxyethylene)siloxane-methyl (polyoxypropylene)siloxane copolymer, dimethylsiloxane-methyl(polyoxyethylene)siloxane copolymer, dimethylsiloxane-methyl(polyoxypropylene)siloxane copolymer, dimethylsiloxane-methylcetyloxysiloxane copolymer, dimethylsiloxane-methylstearoxysiloxane copolymer, and various other silicones. The silicone is preferably methylhydrogen polysiloxane or methylpolysiloxane.

The total content of the UV scattering agent that can be contained in the oil-in-water type emulsified composition of the present invention is 0.1% by weight or more, preferably 0.5% by weight or more, more preferably 1% by weight or more, even more preferably 5% by weight or more, or most preferably 10% by weight or more, relative to the total of the oil-in-water type emulsified composition to function as a sunscreen and 40% by weight or less, preferably 30% by weight or less, more preferably 25% by weight or less, or even more preferably 20% by weight or less, relative to the total of the oil-in-water type emulsified composition to avoid excessive scattering of ultraviolet contained in incident light. The total content of the UV scattering agent that can be contained in the oil-in-water type emulsified composition of the present invention is 0.1 to 40% by weight, 0.1 to 30% by weight, 0.1 to 25% by weight, 0.1 to 20% by weight, 0.5 to 40% by weight, 0.5 to 30% by weight, 0.5 to 25% by weight, 0.5 to 20% by weight, 1 to 40% by weight, 1 to 30% by weight, 1 to 25% by weight, 1 to 20% by weight, 5 to 40% by weight, 5 to 30% by weight, 5 to 25% by weight, 5 to 20% by weight, 10 to 40% by weight, 10 to 30% by weight, 10 to 25% by weight, or 10 to 20% by weight.

(E) Powder

The oil-in-water type emulsified composition of the present invention may contain a powder. The term “powder” refers to a solid substance which is finely crushed. The powder contained in the oil-in-water type emulsified composition of the present invention as long as the powder is commonly used in cosmetics, for example, polymethyl methacrylate, crosslinked silicone/network-type silicone block copolymer, silica, hydrophobized talc, cornstarch, hydrophobized polyurethane. All or a portion of the powder is dispersed in the oil phase of the oil-in-water type emulsified composition of the present invention.

The amount of the powder that can be contained in the oil-in-water type emulsified composition of the present invention is 0.01% by weight or more, preferably 0.05% by mass or more, more preferably 0.1% by weight or more, or even more preferably 0.5% by weight or more, and 20% by weight or less, preferably 15% by weight or less, more preferably 10% by weight or less, or even more preferably 5% by weight or less relative to the total of the oil-in-water type emulsified composition, and is 0.01 to 99.99% by weight, 0.1 to 99.9% by weight, 0.1 to 20% by weight, 0.1 to 15% by weight, 0.1 to 10% by weight, 0.5 to 20% by weight, 0.5 to 10% by weight, or 1 to 10% by weight relative to the total of the oil-in-water type emulsified composition.

(F) Dispersant

The oil-in-water type emulsified composition of the present invention may contain a dispersant. The term “dispersant” refers to a substance which adsorbs on the surface of particles dispersed in a water phase or oil phase whereby the particles can be dispersed homogenously in a water-based or oil-based medium. The dispersant that can be used in the present invention is not particularly limited as long as the function of the UV wavelength conversion substance is not impaired, and is preferably an oil-based dispersant. Examples of the oil-based dispersant include a nonionic surfactant, a cationic surfactant, an anionic surfactant, a silicone-based surfactant, and a fatty acid. Specifically in the present invention, the use of a nonionic surfactant and/or a silicone-based surfactant and/or a fatty acid that are commonly used in cosmetics and pharmaceuticals is preferred.

Preferable examples of the dispersant that can be contained in the oil-in-water type emulsified composition of the present invention include PEG-10 dimethicone, bis-butyldimethicone polyglyceryl-3, PEG-polydimethylpolysiloxane ethyldimethicone, lauryl PEG-polydimethylpolysiloxane ethyldimethicone, cetyl PEG/PPG-10/dimethicone, isostearic acid, diisostearic acid polyglyceryl-2, carboxydecyl trisiloxane, PEG-12 dimethicone, polyoxyethylene sorbitan monostearate, and combinations of two or more thereof.

Preferable examples of the dispersant that can be contained in the oil-in-water type emulsified composition of the present invention, whereby the function of the UV wavelength conversion substance is enhanced, include PEG-10 dimethicone, bis-butyldimethicone polyglyceryl-3, PEG-polydimethylpolysiloxyethyl dimethicone, lauryl PEG-9 polydimethylpolysiloxyethyl dimethicone, cetyl PEG/PPG-10/1dimethicone, isostearic acid, carboxydecyl trisiloxane, and combinations of two or more thereof.

The content of the dispersant in the oil-in-water type emulsified composition of the present invention is not particularly limited as long as the wavelength conversion effect of the present invention is not impaired. The content of the dispersant can be determined according to the type of UV wavelength conversion substance and the application of the oil-in-water type emulsified composition containing the UV wavelength conversion substance, and may be within the range of, for example, 0.01 to 10% by weight or 0.1% to 99.9% by weight.

Preferably, the content of the dispersant in the oil-in-water type emulsified composition of the present invention is 0.1% by weight or more, preferably 0.3% by mass or more, or more preferably 0.5% by weight or more, and 20% by weight or less, preferably 10% by weight or less, more preferably 5% by weight or less, or even more preferably 2% by weight or less relative to the total of the oil-in-water type emulsified composition, and is 0.01 to 99.99% by weight, 0.1 to 99.9% by weight, 0.1 to 20% by weight, 0.1 to 10% by weight, 0.1 to 5% by weight, 0.1 to 3% by weight, 0.1 to 2% by weight, 0.1 to 1% by weight, 0.5 to 10% by weight, 0.5 to 5% by weight, or 0.5 to 2% by weight relative to the total of the oil-in-water type emulsified composition.

As one aspect of the present invention, the dispersant of the oil-in-water type emulsified composition contains bis-butyldimethicone polyglyceryl-3 (KF-6109 by Shin-Etsu Chemical Co., Ltd.). The content of the dispersant in the oil-in-water type emulsified composition is 0.1% by weight or more, preferably 0.3% by mass or more, or more preferably 0.5% by weight or more, and 20% by weight or less, preferably 10% by weight or less, more preferably 5% by weight or less, or even more preferably 2% by weight or less relative to the total of the oil-in-water type emulsified composition, and is 0.01 to 99.99% by weight, 0.1 to 99.9% by weight, 0.1 to 20% by weight, 0.1 to 10% by weight, 0.1 to 5% by weight, 0.1 to 3% by weight, 0.1 to 2% by weight, 0.1 to 1% by weight, 0.5 to 10% by weight, 0.5 to 5% by weight, or 0.5 to 2% by weight relative to the total of the oil-in-water type emulsified composition.

(G) Oil Content

The oil-in-water type emulsified composition of the present invention contains an oil content. The phrase “oil content” refers to a hydrophobic substance that phase-separates from water, which is a component of the oil-in-water type emulsified composition of the present invention. The oil content that can be used in the present invention is not particularly limited and contains one or more of, for example, hydrocarbon oils, ester oils, silicone oils, liquid oils, solid fats, and higher alcohols.

Examples of the hydrocarbon oils include liquid paraffin, tetraisobutane, hydrogenated polydecene, olefin oligomer, isododecane, isohexadecane, squalane, and hydrogenated polyisobutene.

Examples of the ester oils include diisopropyl sebacate, octyl palmitate, cetyl isooctanoate (cetyl 2-ethylhexanoate), triethylhexanoin, neopentyl glycol dicaprate, triisostearin, diisostearyl malate, PPG-3 dipivalate, di-2-ethylhexyl succinate, 2-ethylhexyl 2-ethylhexanoate, polyglyceryl-6 octacaprylate, and glyceryl tri(caprylate/caprate).

Examples of the silicone oils include caprylyl methicone, dimethicone, amino-modified polysiloxane, polyether-modified polysiloxane, alkyl-modified polysiloxane, and fluorine-modified polysiloxane.

Examples of the liquid oils include avocado oil, camellia oil, macadamia nut oil, mink oil, olive oil, castor oil, jojoba oil, triglycerol, glycerol trioctanoate, and isostearic acid.

Examples of the solid fats include coconut oil, hardened coconut oil, palm oil, beef tallow, mutton tallow, Japan wax, and hardened castor oil.

Examples of the higher alcohols include isostearyl alcohol, oleyl alcohol, and butylene glycol-propylene glycol copolymer (for example, PBG/PPG-9/1 copolymer).

The total content of the oil content contained in the oil-in-water type emulsified composition of the present invention is 5% by weight or more, preferably 10% by weight or more, or more preferably 15% by weight or more, relative to the total of the oil-in-water type emulsified composition.

(H) Water-Phase Thickener

The oil-in-water type emulsified composition of the present invention may contain a water-phase thickener in addition to the water-soluble alkyl-substituted polysaccharide derivative. The phrase “water-phase thickener” refers to an additive capable of, when dissolved in water (water phase), increasing the viscosity of a liquid in the water phase. Examples of the water-phase thickener include (dimethylacrylamide/acryloyldimethyltaurin sodium) crosspolymer, succinoglycan, an acrylic-based thickener; cellulose-based thickeners such as cellulose gum, hydroxyethylcellulose, hydroxypropyl methylcellulose, stearoxyhydroxypropyl methylcellulose, hydroxypropyl guar hydroxypropyltrimonium chloride, and a cationized cellulose with a cationic functional group added to cellulose; vinyl-based thickeners such as polyvinyl alcohol, and clay minerals such as bentonite. One or more selected therefrom can be included in the oil-in-water type emulsified composition.

(I) Oil-Phase Thickener

The oil-in-water type emulsified composition of the present invention may contain an oil-phase thickener. The phrase “oil-phase thickener” refers to an additive capable of, when dissolved in the oil phase of the oil-in-water type emulsified composition, increasing the viscosity of a liquid in the oil phase. Examples of the oil-phase thickener include a sugar fatty acid ester, a solid oil, a metal soap, 12-hydroxystearic acid, and inorganic polymers such as bentonite and hectorite. Examples of the sugar fatty acid ester include esters of a fatty acid having 10 to 22 carbon atoms and dextrin, sucrose, or inulin. Specific examples thereof include dextrin palmitate, dextrin myristate, dextrin (palmitate/ethylhexanoate), dextrin stearate, dextrin behenate, dextrin laurate, coconut oil dextrin fatty acid, sucrose palmitic acid ester, sucrose stearic acid ester, and stearoyl inulin. Thereamong, dextrin palmitate, dextrin myristate, dextrin (palmitate/ethylhexanoate), and stearoyl inulin are preferable in terms of usability and stability. One or more selected therefrom can be included in the oil-in-water type emulsified composition.

(Other Components)

Various components can be appropriately blended in the oil-in-water type emulsified composition of the present invention as long as the effect of the present invention is not impaired. Examples of the various components include additive components that can be blended generally in cosmetics, such as a chelating agent (disodium edetate hydrate), a fragrance, a moisturizing agent (glycerin, dipropylene glycol), a preservative, an anionic surfactant, a cationic surfactant, an amphoteric surfactant, a nonionic surfactant, a moisturizing agent, a water-soluble polymer, a film-forming agent such as silicone-modified polysaccharide or (acrylamide/DMAPA acrylate/methoxy PEG methacrylate) copolymer, a metal ion sequestering agent, a lower alcohol, a polyhydric alcohol, various extracts, a sugar, an amino acid, an organic amine, a polymer emulsion, a pH adjuster, skin nutrients, a vitamin, a pharmaceutical, a quasi-drug, a water-soluble drugs applicable to cosmetics, an antioxidant, a buffering agent, an antioxidant aid, an injection agent, a pigment, a dye, a color, water, an acid component, or an alkaline component. These optional components can be appropriately blended in an oil phase or a water phase. Further, another cell activating agent may be contained or co-used to enhance the effect of the present invention.

The oil-in-water type emulsified composition of the present invention may be an oil-in-water type emulsified composition. The oil-in-water type emulsified composition of the present invention can be produced by a conventional method.

Specifically, the oil-in-water type emulsified composition of the present embodiment is obtained in accordance with the following procedures: Component (B) and water are mixed to prepare a water phase. When component (B) is dispersed in the water phase, component (A) or (A′) is mixed therein. Separately, oil-based components such as oil content are mixed to prepare an oil phase. When the oil-based components are dispersed in the oil phase, component (A) or (A′) is mixed therein. To the water phase are added the oil phase and other components, followed by stirring to obtain an oil-in-water type emulsified composition.

One aspect of the oil-in-water type emulsified composition of the present invention is an oil-in-water type emulsified composition containing a powder. Examples of the powder include silica, polymethyl methacrylate, crosslinked silicone/network-type silicone block copolymer, talc, cornstarch, and polyurethane. The oil-in-water type emulsified composition containing a powder of the present invention can be produced by a conventional method.

The oil-in-water type emulsified composition of the present invention can be a sunscreen cosmetic such as a sunscreen cream. The formulation form may be, for example, an emulsion or a cream. The oil-in-water type emulsified composition of the present invention imparts a refreshing feel after use compared to a water-in-oil type. When coated on skin, there is a unique fresh feeling after use which does not leave a feeling of residue

The oil-in-water type emulsified composition of the present invention can be used by applying it to any of skin, in particular, skin excluding hair, preferably face, body, limbs, preferably by coating any thereof with the emulsified composition. For example, by the application, preferably coating, of the oil-in-water type emulsified composition of the present embodiment, not only can skin be protected from ultraviolet to suppress adverse effects on the skin, but the skin can also be imparted with natural and preferable appearance via activation of skin cells.

EXAMPLES

The present invention will be described in more detail with reference to the following Examples. Note that the present invention is not limited thereto.

Example 1: Cell Activation Effects of Various UV Wavelength Conversion Substances Experiment 1-1: Preparation of UV Wavelength Conversion Substance

A UV wavelength conversion substance was prepared as follows:

(1) B-phycoerythrin

B-phycoerythrin was obtained from Porphyridium cruentum extract. The absorption spectrum thereof had a peak wavelength of 305 nm, and the emission spectrum thereof had peak wavelengths of 570 nm and 610 nm.

(2) C-phycocyanin

C-phycocyanin was obtained from Spirulina platensis extract. The absorption spectrum thereof had a peak wavelength of 350 nm, and the emission spectrum thereof had peak wavelengths of 640 nm and 700 nm. Linablue by DIC Corp. was used.

(3) Zinc Oxide Phosphor

Lumate G by Sakai Chemical Industry Co., Ltd. was used. Lumate G is a zinc oxide phosphor of ZnO doped with a sulfur-containing compound, as described in WO 2018/004006. The absorption spectrum thereof had a peak wavelength of 365 nm, and the emission spectrum thereof had a peak wavelength of 510 nm.

(4) Magnesium Titanate Phosphor

Lumate R by Sakai Chemical Industry Co., Ltd. was used. Lumate R is a magnesium titanate phosphor of MgTiO₃ doped with manganese. The absorption spectrum thereof had a peak wavelength of 365 nm, and the emission spectrum thereof had a peak wavelength within a zone of 660 to 680 nm.

The UV wavelength conversion substances (1) and (2) were dissolved in water to prepare solutions having a concentration of 1% or 5%.

The UV wavelength conversion substances (3) and (4) were dispersed in alcohol to prepare 5% and 10% dispersions.

Experiment 1-2: Preparation of Cell Sample

A cell sample was prepared as follows:

1. Human dermal fibroblasts and human skin keratinocytes purchased from Kurabo Industries Ltd. were used. A cell suspension (1 mL) stored in liquid nitrogen was thawed in a water bath (37° C.) to an extent that small ice pellets remained, and then diluted with 9 mL of warm medium. 2. The diluted suspension was mixed gently and then transferred to a T75 flask and incubated overnight at 37° C. 3. The next day, the medium was replaced with 10 mL of fresh medium. 4. The medium was replaced periodically (once every 2 days for fibroblasts and once every 2 to 3 days for keratinocytes) and cell proliferation was continued. Meanwhile, the cells were observed using a microscope, and it was confirmed that the cells grew in the correct form. 5. After the cells reached about 80% confluence, the cells were passaged. The cells were passaged by washing the cells once with 10 mL of warm PBS, adding 5 mL of warm trypsin to a T75 flask, covering the bottom of the flask with a trypsin solution, followed by aspirating at room temperature for 1 minute. 6. The flask was allowed to stand in an oven at 37° C. for (maximum) 2 minutes for fibroblasts and (maximum) 7 minutes for keratinocytes. The cells were observed using a microscope and confirmed to be small and oval. 7. Thereafter, the side of the T75 flask was lightly tapped to release the cells. The cells were observed using a microscope and confirmed to be moving freely. 8. Fibroblasts were resuspended in 5 mL warm FGM (containing 10% serum) and transferred to a sterile 50 mL Falcon tube. An additional 5 mL of warm FGM was used to flush the flask and added to the Falcon tube to ensure transfer of all cells. 9. The cells were centrifuged at 10,000 rpm for 5 minutes (4° C.) and the supernatant was removed taking care not to disturb the pellet of cells. 10. Depending on the cell type, fibroblasts were resuspended in FGM or KGM at a concentration of 2×10⁴ cells/well (500 μL), and keratinocytes were resuspended in FGM or KGM at a concentration of 4×10⁴ cells/well (500 μL) and plated 24-well plates. 11. Cells were seeded in 24-well plates and the media were changed periodically (once every 2 days for fibroblasts and once every 2 to 3 days for keratinocytes) and the cells were grown until 60 to 70% confluence (depending on the type of experiment) was reached. (Note: Fibroblasts should reach the desired confluency in 24 hours at a cell density of 2×10⁴ cells/well. When the cell density is low, for example, 1×10⁴ cells/well, it takes 48 hours for fibroblasts to reach the desired confluency.) 12. 24 hours before irradiation, the medium was changed to a supplement-free medium (in the case of keratinocytes) or a medium containing a low concentration of serum (0.5% FCS) (in the case of fibroblasts).

Experiment 1-3: Ultraviolet Irradiation

1. A solar simulator was turned on at least 30 minutes before irradiation to warm up a lamp. The solar simulator was set to use a UG11 filter. UG11 filters are filters that allow only UVB to pass and cut light of other wavelengths. The UV light passed through the UG11 filter had a peak wavelength of 300 nm to 385 nm. 2. A temperature control plate was turned on and set to 33° C. 3. The cells prepared in Experiment 1-2 were washed once with warm PBS. 4. To each well was added 0.5 mL of a warmed Martinez solution (145 mM NaCl, 5.5 mM KCl, 1.2 mM MgCl₂.6H₂O, 1.2 mM NaH₂PO₄.2H₂O, 7.5 mM HEPES, 1 mM CaCl₂, and 10 mM D-glucose). 5. As depicted in FIG. 1, cell wells were placed on a plate. Then, 0.4 ml of a solution containing the UV wavelength conversion substances (1) to (4) prepared in Experiment 1-1 was injected into each well of a 24-well plate. The wells containing cells were placed to be covered, such that the cell solution was irradiated with UV light through the solution of the UV wavelength conversion substances without direct contact between the UV wavelength conversion substance solution and the cell solution. 6. Irradiation was carried out to a total dose of 100 mJ/cm². Further, as controls, there were prepared a sample of cells irradiated directly with UV light without placing a plate of a UV wavelength conversion substance on cell wells and a sample of cells cultured in the dark without irradiation with UV light. 7. After irradiation, the Martinez was replaced with warm KGM (without supplements) or FGM (containing 0.5% FCS) and the plate was returned to the incubator at 37° C.

Experiment 1-4: Measurement of Cell Activity

After the completion of Experiment 1-3, the cells maintained in the incubator for 48 hours were used to measure the activity by the following method:

1. A medium (KGM medium without supplements or 0.5% FCS-containing FGM medium) was supplemented with 10% AlamarBlue and warmed to 37° C. 2. The medium in the wells was replaced with 500 μL of the above 10% AlamarBlue solution, and the plate was returned to the incubator at 37° C. for about 3 hours. Control wells were also maintained in the incubator. These solutions were maintained in the dark to protect them from light. 3. After 3 hours, 100 μL aliquots were collected and transferred to a black 96-well plate. 4. Fluorescence measurement values at 544 nm/590 nm were read using a fluorometer (OPwave +, Ocean Photonics).

The results are shown in FIG. 2. UV irradiation reduced cell activity compared to the control without irradiation. However, the activity of cells irradiated with UV through any UV wavelength conversion substance was increased compared to the control without irradiation. From the above results, it was found that although the cell activity was decreased by UV irradiation, the decrease in cell activity is suppressed using a UV wavelength conversion substance.

Example 2: Influence of Concentration of UV Wavelength Conversion Substance or Intensity of UV on Cell Activity

The same method as in Experiment 1 was employed except that C-phycocyanin was used as the UV wavelength conversion substance, a cell culture was covered with a plate of a solution containing C-phycocyanin at 0%, 0.4%, or 2%, and irradiated with UV at a dose of 0, 10, 25, 50, 75, or 100 mJ/cm².

The results are shown in FIG. 3. When the UV wavelength conversion substance was not used, the cell activity decreased as the UV irradiation amount increased. However, when 0.4% C-phycocyanin was added, the decrease in cell activity was suppressed even when UV irradiation was carried out, and when 2% C-phycocyanin was added, the cell activity was even increased compared to the case where UV irradiation was not carried out. From the above results, it was found that although the cell activity was decreased by UV irradiation, the use of a UV wavelength conversion substance not only suppressed the decrease in cell activity in a concentration-dependent manner, but also enhanced the cell activity.

Example 3: Restoration of Cell Activity Decreased by UV Irradiation

The same method as in Experiment 1 was employed except that as shown in FIG. 4, UV irradiation was carried out without using a UV wavelength conversion substance until the irradiation amount reached 400 mJ/cm² to once decrease the cell activity, and a cell culture was covered with a plate of a solution containing C-phycocyanin as the UV wavelength conversion substance at 0%, 0.4%, or 2%, and irradiated with UV at a dose of 0, 10, 25, 50, 75, 100, or 200 mJ/cm².

The results are shown in FIG. 5. It can be seen that cell activity was recovered by subjecting even cells having once decreased activity by UV irradiation without using a UV wavelength conversion substance to UV irradiation using a UV wavelength conversion substance. This effect of C-phycocyanin was equivalent at concentrations of 0.4% and 2%, suggesting a sufficient cell activation effect at 0.4%. On the other hand, when UV irradiation was carried out without using a UV wavelength conversion substance, the cell activity decreased in a UV dose-dependent manner.

The results for human dermal fibroblasts are described above. Similar results were also observed for keratinocytes (data not shown). From these results, it was found that a UV wavelength conversion substance not only suppressed a decrease in cell activity due to UV irradiation, but also has an effect of activating cells using UV light. When skin cells are activated, prevention of and improvement from wrinkles, spots, skin aging, photoaging, etc. are expected.

From Examples 1 to 3 above, it was considered that a UV wavelength conversion substance converts the wavelength of ultraviolet, and emitted visible light (fluorescence having a main wavelength of 500 nm to 700 nm) activates skin cells such as fibroblasts and corneocytes. Thus, various oil-in-water type emulsified compositions containing a UV wavelength conversion substance were produced, and the amount of fluorescence emitted during ultraviolet irradiation was evaluated.

For fluorescence measurement, the oil-in-water type emulsified composition was applied to an S plate (refer to Japanese Registered Patent Publication No. 4453995) at 2 mg/cm² and dried to prepare a coating film of the oil-in-water type emulsified composition. The obtained coating film was irradiated with ultraviolet having a predetermined wavelength, and a fluorescence integrated value in a predetermined wavelength region was measured using a fluorescence spectrophotometer RF-5300PC (Shimadzu Corporation). When the UV wavelength conversion substance was a zinc oxide phosphor, a coating film was irradiated with ultraviolet at 365 nm, and the fluorescence integrated value of 400 to 600 nm was measured in the same manner. When the UV wavelength conversion substance was a magnesium titanate phosphor, a coating film was irradiated with ultraviolet at 340 nm, and the fluorescence integrated value of 550 to 800 nm was measured in the same manner. When the UV wavelength conversion substance was C-phycocyanin, a coating film was irradiated with ultraviolet light at 350 nm, and fluorescence integrated values at 550 to 800 nm were measured in the same manner. When the UV wavelength conversion substance was vitamin B2, a coating film was irradiated with ultraviolet at 270 nm, and the fluorescence integrated value at 400 to 750 nm was measured in the same manner.

Example 4: Oil-In-Water Type Emulsified Composition (Zinc Oxide Phosphor)

Oil-in-water type emulsified compositions (Formulation Examples 1 to 4) having the compositions shown in Table 1 were produced according to a conventional production process. Formulation Example 1 (Comparative Example) did not contain stearoxyhydroxypropyl methylcellulose. Formulation Examples 2 to 4 contained stearoxyhydroxypropyl methylcellulose in amounts of 0.04, 0.1, and 0.2% by weight, respectively, relative to the total of the respective oil-in-water type emulsified composition. All Formulation Examples contained a zinc oxide phosphor as the UV wavelength conversion substance. All Formulation Examples were oil-in-water type emulsified compositions and thus imparted a refreshing feel after use. The obtained oil-in-water type emulsified compositions were irradiated with ultraviolet of 365 nm, and fluorescence integrated values at wavelengths of 400 to 600 nm were measured. The Comparative Example had a fluorescence integrated value of 3268, whereas Formulation Examples 2, 3, and 4 had fluorescence integrated values of 3783, 4149, and 3627, respectively. It was found that the addition of stearoxyhydroxypropyl methylcellulose at any concentration enhanced the wavelength conversion function of the zinc oxide phosphor, and stearoxyhydroxypropyl methylcellulose at a concentration of 0.1% by weight enhanced the wavelength conversion function the most.

TABLE 1 Formulation Formulation Formulation Formulation Formulation composition Example 1 Example 2 Example 3 Example 4 Water water Total amount of 100 with water Alcohol ethanol 5 5 5 5 Moisturizing glycerin 3 3 3 3 agent butylene glycol 5 5 5 5 Surfactant PEG-100 hydrogenated castor oil 1 1 1 1 Film-forming (acrylamide/DMAPA agent acrylate/methoxy PEG 1 1 1 1 methacrylate) copolymer Water-phase (dimethylacrylamide/ thickener acryloyldimethyltaurin sodium) 0.2 0.2 0.2 0.2 crosspolymer stearoxyhydroxypropyl 0 0.04 0.1 0.2 methylcellulose succinoglycan 0.2 0.2 0.2 0.2 dextrin (palmitate/ethylhexanoate) 0.5 0.5 0.5 0.5 Oil content diisopropyl sebacate 7 7 7 7 caprylyl methicone 10 10 10 10 Dispersant isostearic acid 1 1 1 1 bis-butyldimethicone polyglyceryl-3 0.5 0.5 0.5 0.5 UV absorber ethylhexyl salicylate 5 5 5 5 ethylhexyl triazone 1 1 1 1 bis(ethylhexyloxyphenol) 1 1 1 1 methoxyphenyl triazine hexyl diethylaminohydroxybenzoyl 1 1 1 1 benzoate UV scattering fine particulate zinc oxide 2 2 2 2 agent particulate titanium 1 1 1 1 Phosphor zinc oxide phosphor 3 3 3 3 Powder silica 1 1 1 1 pH adjuster pH adjuster q.s. q.s. q.s. q.s. Preservative preservative q.s. q.s. q.s. q.s. Fragrance fragrance q.s. q.s. q.s. q.s. Fluorescence integrated value 3268 3783 4149 3627

Example 5: Oil-In-Water Type Emulsified Composition (Magnesium Titanate Phosphor)

Oil-in-water type emulsified compositions (Formulation Examples 5 and 6) having the compositions shown in Table 2 were produced according to a conventional production process. Formulation Example 5 (Comparative Example) did not contain stearoxyhydroxypropyl methylcellulose. Formulation Example 6 contained stearoxyhydroxypropyl methylcellulose in an amount of 0.1% by weight relative to the total of the oil-in-water type emulsified composition. Both Formulation Examples contained a magnesium titanate phosphor as the UV wavelength conversion substance. Both Formulation Examples were oil-in-water type emulsified compositions and thus imparted a refreshing feel after use. The obtained oil-in-water type emulsified compositions were irradiated with ultraviolet of 365 nm, and fluorescence integrated values at wavelengths of 400 to 600 nm were measured. The Comparative Example had a fluorescence integrated value of 2397, whereas Formulation Example 6 had a fluorescence integrated value of 3674. It was found that the addition of stearoxyhydroxypropyl methylcellulose enhanced the wavelength conversion function of the magnesium titanate phosphor.

TABLE 2 Formulation Formulation Formulation composition Example 5 Example 6 Water water Total amount of 100 with water Alcohol ethanol 5 5 Moisturizing glycerin 3 3 agent butylene glycol 5 5 Surfactant PEG-100 hydrogenated 1 1 castor oil Film-forming (acrylamide/DMAPA 1 1 agent acrylate/methoxy PEG methacrylate) copolymer Water-phase (dimethylacrylamide/ 0.2 0.2 thickener acryloyldimethyltaurin sodium) crosspolymer stearoxyhydroxypropyl 0.1 methylcellulose succinoglycan 0.2 0.2 dextrin 0.5 0.5 (palmitate/ ethylhexanoate) Oil content diisopropyl sebacate 7 7 caprylyl methicone 10 10 Dispersant isostearic acid 1 1 bis-butyldimethicone 0.5 0.5 polyglyceryl-3 UV absorber ethylhexyl salicylate 5 5 ethylhexyl triazone 1 1 bis(ethylhexyloxyphenol) 1 1 methoxyphenyl triazine hexyl 1 1 diethylaminohydroxy- benzoyl benzoate UV scattering fine particulate 2 2 agent zinc oxide particulate titanium 1 1 Phosphor magnesium titanate 3 3 phosphor Powder silica 1 1 pH adjuster pH adjuster q.s. q.s. Preservative preservative q.s. q.s. Fragrance fragrance q.s. q.s. Fluorescence integrated 2397 3674 value

Example 6: Oil-In-Water Type Emulsified Composition (Phycocyanin)

Oil-in-water type emulsion compositions (Formulation Examples 7 and 8) having the compositions shown in Table 3 were produced according to a conventional production process. Formulation Example 7 (Comparative Example) did not contain stearoxyhydroxypropyl methylcellulose. Formulation Example 8 contained stearoxyhydroxypropyl methylcellulose in amount of 0.1% by weight relative to the total of the oil-in-water type emulsified composition. Both Formulation Examples contained C-phycocyanin as the UV wavelength conversion substance. Both Formulation Examples were oil-in-water type emulsified compositions and thus imparted a refreshing feel after use. The obtained oil-in-water type emulsified compositions were irradiated with ultraviolet of 350 nm, and fluorescence integrated values at wavelengths of 550 to 800 nm were measured. The Comparative Example had a fluorescence integrated value of 2834, whereas Formulation Example 8 had a fluorescence integrated value of 3214. It was found that the addition of stearoxyhydroxypropyl methylcellulose enhanced the wavelength conversion function of the phycocyanin.

TABLE 3 Formulation Formulation Formulation composition Example 7 Example 8 Water water Total amount of 100 with water Alcohol ethanol 5 5 Moisturizing glycerin 3 3 agent butylene glycol 5 5 Surfactant PEG-100 hydrogenated 1 1 castor oil Film-forming (acrylamide/DMAPA 1 1 agent acrylate/methoxy PEG methacrylate) copolymer Water-phase (dimethylacrylamide/ 0.2 0.2 thickener acryloyldimethyltaurin sodium) crosspolymer stearoxyhydroxypropyl 0 0.1 methylcellulose succinoglycan 0.2 0.2 dextrin 0.5 0.5 (palmitate/ethylhexanoate) Oil content diisopropyl sebacate 7 7 caprylyl methicone 10 10 Dispersant isostearic acid 1 1 bis-butyldimethicone 0.5 0.5 polyglyceryl-3 UV absorber ethylhexyl salicylate 5 5 ethylhexyl triazone 1 1 bis(ethylhexyloxyphenol) 1 1 methoxyphenyl triazine hexyl diethylaminohydroxy- 1 1 benzoyl benzoate UV scattering fine particulate zinc oxide 2 2 agent particulate titanium 1 1 Phosphor phycocyanin 0.1 0.1 Powder silica 1 1 pH adjuster pH adjuster q.s. q.s. Preservative preservative q.s. q.s. Fragrance fragrance q.s. q.s. Fluorescence integrated value 2834 3214

Example 7: Oil-In-Water Type Emulsified Composition (Vitamin B2)

Oil-in-water type emulsion compositions (Formulation Examples 9 and 10) having the compositions shown in Table 4 were produced according to a conventional production process. Formulation Example 9 (Comparative Example) did not contain stearoxyhydroxypropyl methylcellulose. Formulation Example 10 contained stearoxyhydroxypropyl methylcellulose in an amount of 0.1% by weight relative to the total of the oil-in-water type emulsified composition. Both Formulation Examples contained vitamin B2 (riboflavin) as the UV wavelength conversion substance. Both Formulation Examples were oil-in-water type emulsified compositions and thus imparted a refreshing feel after use. The obtained oil-in-water type emulsified compositions were irradiated with ultraviolet of 270 nm, and fluorescence integrated values at wavelengths of 400 to 750 nm were measured. The Comparative Example had a fluorescence integrated value of 6726, whereas Formulation Example 10 had a fluorescence integrated value of 6986. It was found that the addition of stearoxyhydroxypropyl methylcellulose enhanced the wavelength conversion function of the vitamin B2.

TABLE 4 Formulation Formulation Formulation composition Example 9 Example 10 Water water Total amount of 100 with water Alcohol ethanol 5 5 Moisturizing glycerin 3 3 agent butylene glycol 5 5 Surfactant PEG-100 hydrogenated 1 1 castor oil Film-forming (acrylamide/DMAPA acrylate/ 1 1 agent methoxy PEG methacrylate) copolymer Water-phase (dimethylacrylamide/acryloyl- 0.2 0.2 thickener dimethyltaurin sodium) crosspolymer stearoxyhydroxypropyl 0 0.1 methylcellulose succinoglycan 0.2 0.2 dextrin 0.5 0.5 (palmitate/ethylhexanoate) Oil content diisopropyl sebacate 7 7 caprylyl methicone 10 10 Dispersant isostearic acid 1 1 bis-butyldimethicone 0.5 0.5 polyglyceryl-3 UV absorber ethylhexyl salicylate 5 5 ethylhexyl triazone 1 1 bis(ethylhexyloxyphenol) 1 1 methoxyphenyl triazine hexyl diethylamino- 1 1 hydroxybenzoyl benzoate UV scattering fine particulate zinc oxide 2 2 agent particulate titanium 1 1 Phosphor vitamin B2 0.01 0.01 Powder silica 1 1 pH adjuster pH adjuster q.s. q.s. Preservative preservative q.s. q.s. Fragrance fragrance q.s. q.s. Fluorescence integrated value 6726 6986

The oil-in-water type emulsified composition of the present invention is described above. However, the present invention is not limited thereto, and can be modified as appropriate without departing from the spirit of the invention. 

1. An oil-in-water type emulsified composition comprising (A) a UV wavelength conversion substance and (B) a water-soluble alkyl-substituted polysaccharide derivative.
 2. The oil-in-water type emulsified composition according to claim 1, wherein the (A) UV wavelength conversion substance comprises an inorganic UV wavelength conversion sub stance.
 3. The oil-in-water type emulsified composition according to claim 2, wherein the inorganic UV wavelength conversion substance comprises one or more selected from the group of a zinc oxide phosphor, a magnesium titanate phosphor, and a calcium phosphate phosphor.
 4. The oil-in-water type emulsified composition according to claim 1, wherein the (A) UV wavelength conversion substance comprises an organic UV wavelength conversion sub stance.
 5. The oil-in-water type emulsified composition according to claim 4, wherein the organic UV wavelength conversion substance comprises one or more selected from the group of: phycocyanin, phycoerythrocyanin, phycoerythrin, vitamin K, vitamin B1, vitamin B2, vitamin B2 derivatives, vitamin B6, vitamin B12, folic acid, salicylic acid, gardenia color, capsicum color, capsicum extract, paprika color, perilla color, red cabbage color; a blue phosphor comprising an amorphous silica particle, cerium, and phosphorus and/or magnesium; a red phosphor comprising a europium-activated compound of a mixed crystal of an alkaline earth metal sulfide and a gallium compound; a phosphor doped with a sulfur-containing compound, and a calcium phosphate phosphor.
 6. The oil-in-water type emulsified composition according to claim 1, comprising both an inorganic UV wavelength conversion substance and an organic UV wavelength conversion substance as the (A) UV wavelength conversion sub stance.
 7. An oil-in-water type emulsified composition comprising: (A′) one or more selected from the group of phycocyanin, phycoerythrocyanin, phycoerythrin, vitamin K, vitamin B1, vitamin B2, vitamin B2 derivatives, vitamin B6, vitamin B12, folic acid, salicylic acid, gardenia color, capsicum color, capsicum extract, paprika color, perilla color, red cabbage color; a blue phosphor comprising an amorphous silica particle, cerium, and phosphorus and/or magnesium; a red phosphor comprising a europium-activated compound of a mixed crystal of an alkaline earth metal sulfide and a gallium compound; a zinc oxide phosphor, a phosphor doped with a sulfur-containing compound, a magnesium titanate phosphor, and a calcium phosphate phosphor, and (B) a water-soluble alkyl-substituted polysaccharide derivative.
 8. The oil-in-water type emulsified composition according to claim 1, wherein the (B) water-soluble alkyl-substituted polysaccharide derivative comprises a C14-22 alkyl-substituted polysaccharide derivative.
 9. The oil-in-water type emulsified composition according to claim 8, wherein the C14-22 alkyl-substituted polysaccharide derivative comprises a stearoxyhydroxypropyl methylcellulose.
 10. The oil-in-water type emulsified composition according to claim 1, further comprising (C) a UV absorber and/or (D) a UV scattering agent.
 11. The oil-in-water type emulsified composition according to claim 1, wherein further (E) a powder is dispersed in an oil phase.
 12. The oil-in-water type emulsified composition according to claim 1, which is a sunscreen cosmetic.
 13. The oil-in-water type emulsified composition according to claim 1, which exhibits a fluorescence intensity increasing effect.
 14. The oil-in-water type emulsified composition according to claim 1, which exhibits a cell activation effect. 